ABSTRACT ? PROJECT 3 Airway inflammation, remodeling, and hyper-reactivity are defining features of asthma, and typically associated with higher than normal levels of nitric oxide (NO). Bronchodilators, such as beta-agonists targeting the ?- adrenergic receptor (?AR)-cyclic AMP pathway, are the backbone of current therapy. However, asthmatic patients have heritable variability of beta-agonist response and some become unresponsive to beta-agonists with time, all of which limit therapeutic efficacy. Soluble Guanylate Cyclase (sGC) is the NO receptor and triggers smooth muscle relaxation, but paradoxically, the high NO in asthma is associated with greater airway hyper-reactivity. TPPG Cycle I studies identified that high levels of NO and oxidants in asthmatic airways damage sGC, making it NO-insensitive and diminishing the NO-sGC pathway from acting in bronchodilation. In preliminary data with Core C, CII-Project 3 now shows that pre-constricted human and murine airways bronchodilate in response to a new class of drugs that target the two states of sGC: its NO-sensitive form (stimulators), and its NO-insensitive damaged form (activators). In the ovalbumin and house dust mite murine models of asthma, single acute administration of an sGC-activating drug induces bronchodilation and prevents airway hyper-reactivity in response to methacholine. Together with Core B and Pharma partners, Project 3 aims to reposition the sGC-activating class of therapeutics - recently launched by Bayer and Ironwood for pulmonary hypertension and inflammatory bowel diseases, respectively - for the treatment of asthma. Project 3 tests the hypothesis that sGC drugs can be repurposed for asthma by: (Aim 1) comparing the efficacy of sGC activators/stimulators with beta-agonist drugs in preclinical models of asthma endotypes (TH2 and TH17); (Aim 2) analyzing mechanistic endotypes of sGC inactivation and/or ?AR dysfunction that underlie the abnormalities in bronchomotor tone, airway inflammation, and remodeling in preclinical models; and (Aim 3) testing blood cells of asthmatic patients in comparison to controls for sGC and ?AR activities to develop a bronchodilator(s) drug response profile test. An ability to define asthmatic populations who would likely benefit from specific classes of bronchodilators (sGC and beta-agonist), using our new functional biomarker assessment of bronchodilator response, will be a large step forward in personalized medicine approaches for asthma, and reveal the market share available for the sGC class of bronchodilators. Project 3 works synergistically with Project 2 and Core B in preclinical asthma, and with Projects 1, 2 and Core A for clinical studies. Core B and Project 3 have designed strong pre-clinical translational studies that are essential to obtain FDA approval to test sGC compounds for an asthma indication, and developed solid Pharma partnerships that have already led to provision of sGC activators/stimulators and key laboratory support for our pharmacodynamic investigations. The focus of translation and commercialization in Project 3 is to obtain preclinical and clinical data required to reposition drugs that are currently FDA-approved for other diseases for FDA-indication of asthma treatment.